Introduction to Lasers

The English name of laser is LASER, which is an acronym for "light amplification by stimulated emission of radiation" (light amplification by stimulated emission of radiation).

The principle of laser generation:

      When an electron in an atom absorbs energy and jumps from a lower energy level to a higher energy level, and then falls back from the higher energy level to the lower energy level, the energy released is emitted in the form of a photon. Being induced (excited) out of the photon beam (laser), which the photon optical properties are highly consistent. Therefore, the laser is monochromatic, directional and brighter than ordinary light sources.

Advantageous features of lasers

    Good monochromaticity: The light emitted by the laser has a narrow wavelength distribution, so the color is extremely pure. The monochromaticity of laser is much stronger than other monochromatic light sources.

Good monochromaticity can facilitate the filtering of light to improve the signal-to-noise ratio. In material processing, different materials absorb different spectra, the monochromaticity of the laser is very good control of the depth of absorption and distribution, can be selected and controlled to deal with materials. Monochromatic light in the optical design is much more convenient, there is no dispersion phase difference, and the better the monochromaticity, the more stable the corresponding wavelength or frequency.

   Strong directionality: The beam emitted by the laser is shot in only one direction. Ordinary light sources are mostly scattered in all directions, if you want to make the light source to reach a part of the convergence, it is necessary to install auxiliary devices, such as automobile headlights are installed with the role of the reflector of the spotlight, so that the light pooled up to shoot in one direction.

  Good coherence: Coherence indicates the degree to which light tends to interfere with each other. If light is considered as a wave, the closer the bands are to each other the higher the coherence. For example, when different waves on the water surface collide with each other, they may enhance each other or cancel each other out, and in the same way as this phenomenon, the more random the waves interfere with each other, the weaker the degree of interference.